Showtime’s “The Tudors” — the period piece about Henry VIII and how people in the 16th century were all clean and had excellent teeth — is inexplicably headed to a third season, and whoopty-doo, it’s got a new poster. Jonathan Rhys Meyers is sitting on a throne of naked women AND men. It was supposed to be just women, but Rhys Meyers insisted, and you can’t deny someone with the prissy pretty-boy starpower of Jonathan Rhys Meyers. I mean, as Showtime actors go, he’s almost as famous as Anna Paquin.